CN113314294B

CN113314294B - Inductor component and method for manufacturing inductor component

Info

Publication number: CN113314294B
Application number: CN202110217982.XA
Authority: CN
Inventors: 吉冈由雅; 今枝大树; 大谷慎士
Original assignee: Murata Manufacturing Co Ltd
Current assignee: Murata Manufacturing Co Ltd
Priority date: 2020-02-26
Filing date: 2021-02-26
Publication date: 2023-12-22
Anticipated expiration: 2041-02-26
Also published as: CN113314294A; US20210265097A1; JP7230850B2; US11842842B2; JP2021136309A

Abstract

The present invention relates to an inductor component and a method of manufacturing the inductor component. The inductor component (10) is provided with: a magnetic layer (21) in which metal magnetic powder (20B) is dispersed in a base material (20A) made of an insulating material; and an inductor wiring (30) which is laminated on the surface of the magnetic layer (21), wherein the inductor wiring (30) has an anchor (34), and the anchor (34) extends from the main surface (MF) on the magnetic layer (21) side of the inductor wiring (30) to cover the surface of the metal magnetic powder (20B) in the magnetic layer (21).

Description

Inductor component and method for manufacturing inductor component

Technical Field

The present invention relates to an inductor component and a method of manufacturing the inductor component.

Background

In the inductor component described in patent document 1, an inductor wiring is laminated on the surface of an insulating substrate. The surface of the inductor wiring on the opposite side of the insulating substrate is covered with an insulating layer. Further, the inductor wiring, the insulating substrate, and the insulating layer are covered with a magnetic layer.

Patent document 1: japanese patent laid-open No. 2013-225718

In the inductor component described in patent document 1, the thickness of the inductor component is increased by an amount corresponding to the insulating substrate. Therefore, it is considered to omit the insulating substrate and directly laminate the inductor wiring on the magnetic layer. However, there is a concern that the adhesion between the magnetic layer and the inductor wiring cannot be sufficiently ensured due to the material of the two. Therefore, in order to reduce the thickness of the inductor component, it is not practical to simply omit the insulating substrate and directly laminate the inductor wiring on the magnetic layer.

Disclosure of Invention

In order to solve the above problems, one aspect of the present invention provides an inductor component comprising: a magnetic layer in which metal magnetic powder is dispersed in a base material made of an insulating material; and an inductor wiring which is laminated on the surface of the magnetic layer, wherein the inductor wiring has an anchor portion which extends from the main surface of the inductor wiring on the magnetic layer side and covers the surface of the metal magnetic powder in the magnetic layer.

According to the above configuration, since the inductor wiring has the anchor portion, an anchor effect can be obtained between the inductor wiring and the magnetic layer. Therefore, even if the inductor wiring and the magnetic layer are directly in contact with each other without interposing another layer therebetween, the required adhesion can be ensured.

In order to solve the above problems, one embodiment of the present invention provides a method for manufacturing an inductor component, comprising: a covering step of covering a part of the surface of the first magnetic layer with a resist layer, wherein the first magnetic layer is formed by dispersing metal magnetic powder in a base material made of an insulating material, and a part of the metal magnetic powder is exposed on the surface; an inductor wiring processing step of immersing the first magnetic layer after the covering step in a plating solution to laminate inductor wiring on a portion of the surface of the first magnetic layer that is not covered with the resist layer; and a resist layer removing step of removing the resist layer after the inductor wiring processing step, wherein the inductor wiring is formed on the surface of the metal magnetic powder exposed on the surface of the first magnetic layer in the inductor wiring processing step.

According to the above configuration, the inductor wiring is also formed on the surface of the metal magnetic powder in the first magnetic layer, so that an anchor effect can be obtained between the inductor wiring and the magnetic layer. Therefore, even if the inductor wiring and the magnetic layer are directly in contact with each other without interposing another layer therebetween, the required adhesion can be ensured.

Even if the inductor wiring is in direct contact with the magnetic layer, a desired adhesion between the inductor wiring and the magnetic layer can be ensured.

Drawings

Fig. 1 is an exploded perspective view of an inductor component of a first embodiment.

Fig. 2 is a top view of the second layer of the first embodiment.

Fig. 3 is a cross-sectional view of the inductor component of the first embodiment taken along line A-A in fig. 2.

Fig. 4 is an enlarged cross-sectional view of a contact portion between the inductor wiring and the magnetic layer in the first embodiment.

Fig. 5 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 6 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 7 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 8 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 9 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 10 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 11 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 12 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 13 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 14 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 15 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 16 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 17 is an explanatory diagram of a method of manufacturing an inductor component according to the first embodiment.

Fig. 18 is an exploded perspective view of the inductor component of the second embodiment.

Fig. 19 is a top view of a second layer of a second embodiment.

Fig. 20 is a cross-sectional view of the inductor component of the second embodiment taken along line B-B in fig. 19.

Fig. 21 is an enlarged cross-sectional view of a contact portion of an inductor wiring and a magnetic layer of the second embodiment.

Fig. 22 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 23 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 24 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 25 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 26 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 27 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 28 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 29 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 30 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 31 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 32 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 33 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 34 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 35 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 36 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 37 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 38 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Fig. 39 is an explanatory diagram of a method of manufacturing an inductor component according to the second embodiment.

Reference numerals illustrate: 10 … inductor component; 20a … substrate; 20B … metal magnetic powder; 21 … first magnetic layer; 30 … inductor wiring; 30a … catalyst layer; 30B … first wiring layer; 30C … second wiring layer; 34 … anchor; 51 … first vertical wires; 60 … cover layer; 70 … external electrode.

Detailed Description

Hereinafter, an inductor component and an embodiment of the inductor component will be described. In addition, the drawings may show components in an enlarged scale for easy understanding. The dimensional ratio of the constituent elements may be different from the actual dimensional ratio or the dimensional ratio in other figures.

< first embodiment >, first embodiment

A first embodiment of the inductor component will be described below.

As shown in fig. 1, the inductor member 10 has a structure in which three thin plate-like layers are stacked in the thickness direction as a whole. In the following description, the stacking direction of three layers will be described as the up-down direction.

The first layer L1 is substantially square when viewed from the up-down direction. The first layer L1 is constituted by only the first magnetic layer 21. As shown in fig. 4, in the first magnetic layer 21, metal magnetic powder 20B is dispersed in a base material 20A made of an insulating material. Therefore, the first magnetic layer 21 is entirely made of a magnetic material. The base material 20A is composed of an epoxy resin and an inorganic filler having an average particle diameter of 1.0 μm or less. The metal magnetic powder 20B is an alloy of iron, silicon and chromium, and the average particle diameter of the metal magnetic powder 20B is 5.0 μm or less. In the present embodiment, the first layer L1 is the lowest layer in the up-down direction. That is, one of the vertical directions on which the external electrode 70 described later is provided is set as an upper side, and the opposite side is set as a lower side.

As shown in fig. 1, a second layer L2 having a square shape when viewed from the up-down direction is formed on the upper layer in the stacking direction of the first layer L1, which is the same as the first layer L1. In the present embodiment, the surface of the second layer L2 in contact with the first layer L1 is the main surface MF of the second layer L2. The second layer L2 is constituted by the inductor wiring 30, the first dummy wiring 41, the second dummy wiring 42, the inner magnetic circuit portion 22, and the outer magnetic circuit portion 23.

As shown in fig. 2, in the second layer L2, the inductor wiring 30 is constituted by a wiring body 31, a first pad 32, and a second pad 33. The inductor wiring 30 extends in a spiral shape centering on the center of the square in the second layer L2 when viewed from the upper side in the up-down direction. Specifically, the wiring body 31 of the inductor wiring 30 is wound in a spiral shape counterclockwise from the radially outer peripheral end 31A toward the radially inner peripheral end 31B when viewed from the upper side in the up-down direction.

The number of turns of the inductor wiring 30 is determined based on the virtual vector. The start point of the virtual vector is arranged on a virtual center line passing through the center of the wiring width of the inductor wiring 30 and extending in the extending direction of the inductor wiring 30. Further, regarding the virtual vector, when the start point of the inductor wiring 30 is moved from a state of being disposed at one end to the other end of the virtual center line as viewed from the normal direction, the number of turns is determined to be 1.0 turn when the angle of rotation in the direction of the virtual vector is 360 degrees. Thus, for example, if it is wound 180 degrees, the number of turns is 0.5. In the present embodiment, the orientation of the virtual vector virtually arranged on the inductor wiring is rotated by 540 degrees. Therefore, the number of turns around which the inductor wiring 30 is wound is 1.5 turns in the present embodiment.

The first pad 32 is connected to the outer peripheral end 31A of the wiring main body 31. The first pad 32 has a substantially circular shape when viewed from the up-down direction. The diameter of the circle of the first pad 32 is larger than the wiring width of the wiring body 31.

The first dummy wirings 41 extend from the first pads 32 toward the outer edge side of the second layer L2. The first dummy wirings 41 extend to the side surfaces of the second layer L2 and are exposed on the outer surface of the inductor component 10.

The second pad 33 is connected to the inner peripheral end 31B of the wiring main body 31. The second pad 33 has a substantially circular shape when viewed from the up-down direction. The diameter of the circle of the second pad 33 is larger than the wiring width of the wiring body 31.

The second dummy wirings 42 extend from a portion wound 0.5 turn from the outer peripheral end 31A at a portion between the outer peripheral end 31A and the inner peripheral end 31B of the wiring main body 31. The second dummy wirings 42 extend to the side surfaces of the second layer L2 and are exposed on the outer surface of the inductor component 10.

As shown in fig. 4, the inductor wiring 30 has a structure in which a catalyst layer 30A, a first wiring layer 30B, and a second wiring layer 30C are laminated in this order from the first magnetic layer 21 side constituting the first layer L1. The catalyst layer 30A of the inductor wiring 30 contacts the upper surface of the first magnetic layer 21, and forms the main surface MF of the second layer L2. The material of the catalyst layer 30A is palladium. In fig. 4, only the inductor wiring 30 and the first magnetic layer 21 are illustrated, and other configurations are omitted.

The first wiring layer 30B is directly laminated on the upper surface of the catalyst layer 30A. The ratio of copper in the material of the first wiring layer 30B is 99wt% or less, and the ratio of nickel is 0.1wt% or more. The thickness TB of the first wiring layer 30B is one tenth or less of the wiring width of the inductor wiring 30. In the present embodiment, the thickness TB of the first wiring layer 30B is 2.0 μm. Here, in one observation field of view of a cross section along the stacking direction by observation with a 1500-fold microscope, the dimension from the upper end of the first magnetic layer 21 to the upper end of the first wiring layer 30B was measured at 3 points, and the thickness TB of the first wiring layer 30B was determined as an average value of the measured values at these 3 points. In the present embodiment, the thickness TB of the first wiring layer 30B is substantially constant. In addition, the thickness of the catalyst layer 30A is shown exaggerated in fig. 4, but is actually much smaller than the thickness of the first wiring layer 30B, and therefore, in the measurement of the thickness TB of the first wiring layer 30B, even if the measurement is performed from the upper end of the first magnetic layer 21, that is, including the thickness of the catalyst layer 30A, there is no influence. However, if the interface of the catalyst layer 30A can be clearly confirmed, the thickness TB may be measured from the upper surface of the catalyst layer 30A. In addition, the wiring width of the inductor wiring 30 is determined as a 3-point average value near the center in the extending direction in the width dimension of the inductor wiring 30.

The second wiring layer 30C is directly laminated on the upper surface of the first wiring layer 30B. The thickness TC of the second wiring layer 30C is 5 times or more the thickness TB of the first wiring layer 30B. In the present embodiment, the thickness TC of the second wiring layer 30C is 45 μm. Therefore, as shown in fig. 3, the thickness TA of the entire inductor wiring 30 is about 47 μm. The ratio of copper in the material of the second wiring layer 30C is 99wt% or more, and the ratio of nickel is the detection limit or less.

The anchor 34 extends from the main surface MF of the inductor wiring 30. The anchor 34 covers the surface of the metal magnetic powder 20B in contact with the main surface MF, among the plurality of metal magnetic powders 20B in the first magnetic layer 21. Therefore, the anchor 34 extends from the main surface MF into between the base material 20A and the metal magnetic powder 20B in the first magnetic layer 21. The metal magnetic powder 20B covered with the anchor 34 includes a cross section in which one third or more of the surface of the metal magnetic powder 20B is covered with the anchor 34 when the cross section is viewed. In the present embodiment, this cross section is a cross section orthogonal to the main surface MF.

As shown in fig. 1, in the second layer L2, a region inside the inductor wiring 30 is the inner magnetic path portion 22. The material of the inner magnetic circuit portion 22 is the same as that of the first magnetic layer 21. In the second layer L2, the region outside the inductor wiring 30 is the external magnetic circuit portion 23. The material of the outer magnetic circuit portion 23 is the same as that of the first magnetic layer 21. That is, in the present embodiment, the inductor wiring 30 of the inductor component 10 has a single-layer structure.

A third layer L3 having a square shape when viewed from the top-bottom direction, similar to the second layer L2, is laminated on the upper surface of the second layer L2. The third layer L3 is constituted by the first vertical wiring 51, the second vertical wiring 52, and the second magnetic layer 24.

The first vertical wiring 51 is directly connected to the upper surface of the first pad 32 without via other layers. The first vertical wiring 51 has a columnar shape, and the axial direction of the columnar coincides with the up-down direction. The diameter of the circular first vertical wiring 51 is slightly smaller than the diameter of the first pad 32 when viewed from the upper side in the up-down direction. The material of the first vertical wiring 51 is the same as that of the second wiring layer 30C of the inductor wiring 30.

The second vertical wiring 52 is directly connected to the upper side surface of the second pad 33 without via other layers. The second vertical wiring 52 has a columnar shape, and the axial direction of the columnar coincides with the up-down direction. The diameter of the circular second vertical wiring 52 is slightly smaller than the diameter of the second pad 33 when viewed from the upper side in the up-down direction. The material of the second vertical wiring 52 is the same as that of the second wiring layer 30C of the inductor wiring 30. Further, the second wiring layer 30C, the first dummy wiring 41, the second dummy wiring 42, the first vertical wiring 51, and the second vertical wiring 52 of the inductor wiring 30 are integrated. In fig. 2, the first vertical wiring 51 and the second vertical wiring 52 are virtually illustrated by two-dot chain lines.

In the third layer L3, the region other than the first vertical wiring 51 and the second vertical wiring 52 is the second magnetic layer 24. The second magnetic layer 24 has a substantially square shape as the first magnetic layer 21 when viewed from the vertical direction. The material of the second magnetic layer 24 is the same as that of the first magnetic layer 21.

As shown in fig. 3, the upper surface of the third layer L3 is covered with an insulating cover layer 60. The cover layer 60 covers substantially the entire upper surface of the third layer L3, and holes are formed in portions of the third layer L3 corresponding to the first vertical wiring 51 and the second vertical wiring 52.

An external electrode 70 is connected to an upper surface of the first vertical wiring 51. The external electrode 70 penetrates the cover layer 60, and the upper surface of the external electrode 70 is exposed from the cover layer 60. The external electrode 70 has a 3-layer structure and is composed of a copper layer 70A, a nickel layer 70B, and a gold layer 70C in this order from the lower side in the lamination direction. The external electrode 70 is also connected to the upper surface of the second vertical wiring 52 in the same manner. In fig. 1, the cover layer 60 and the external electrode 70 are not shown.

Next, a method of manufacturing the inductor component 10 according to the first embodiment will be described.

As shown in fig. 5, the method for manufacturing the inductor component 10 includes a first magnetic layer processing step, a first covering step, an inductor wiring processing step, a first resist layer removal step, a second covering step, a vertical wiring processing step, a second resist layer removal step, a second magnetic layer processing step, a covering layer processing step, a base substrate removal step, and an external electrode processing step.

In manufacturing the inductor component 10, first, a first magnetic layer processing step is performed. As shown in fig. 6, a base substrate 80 with copper foil is prepared. The base substrate 81 of the base substrate 80 with copper foil is plate-shaped. A copper foil 82 is laminated on the layer on the upper side in the lamination direction of the base substrate 81. As shown in fig. 7, a first magnetic layer 21 composed of a base material 20A and a metal magnetic powder 20B is formed on the upper surface of the copper foil of the base substrate 80 with the copper foil. When forming the first magnetic layer 21, an insulating resin containing the metal magnetic powder 20B is applied, and the insulating resin is solidified by press working to become the base material 20A. Then, the upper side portions of the base material 20A and the metal magnetic powder 20B are ground so that the dimension in the up-down direction of the first magnetic layer 21 becomes a desired dimension. In addition, it is preferable to form a minute gap at the interface between the base material 20A and the metal magnetic powder 20B by adjusting the process parameters at the time of grinding. For example, a minute gap can be formed between the metal magnetic powder 20B exposed from the base material 20A and the base material 20A by vibrating the metal magnetic powder with a grinding tool. More specifically, when the upper portions of the base material 20A and the metal magnetic powder 20B are ground, the metal magnetic powder 20B is harder than the base material 20A made of an insulating resin when the grinding tool is in contact with the base material 20A and the metal magnetic powder 20B, so that the vibration of the metal magnetic powder 20B is large when the grinding tool vibrates accordingly. In this way, a slight gap is formed by the difference in vibration between the base material 20A and the metal magnetic powder 20B.

After the first magnetic layer processing step, a first covering step is performed. As shown in fig. 8, in the first covering step, the first resist layer 91 covering the portions of the upper surface of the first magnetic layer 21 where the inductor wiring 30, the first dummy wiring 41, and the second dummy wiring 42 are not formed is patterned. Specifically, first, a photosensitive dry film resist is applied to the entire upper surface of the first magnetic layer 21. Next, portions of the upper surface of the first magnetic layer 21 where the inductor wiring 30, the first dummy wiring 41, and the second dummy wiring 42 are not formed are exposed. As a result, the exposed portions of the coated dry film resist are cured. Then, the uncured portions in the coated dry film resist are peeled off by a chemical solution. Thereby, a cured portion in the coated dry film resist is formed as the first resist layer 91. On the other hand, in the portion of the coated dry film resist which is removed by the chemical solution but not covered by the first resist layer 91, the first magnetic layer 21 is exposed.

After the first covering process, an inductor wiring process is performed. As shown in fig. 9, in the inductor wiring processing step, an inductor wiring 30 composed of a catalyst layer 30A, a first wiring layer 30B, and a second wiring layer 30C is formed on the upper surface of the first magnetic layer 21. Specifically, first, palladium is adsorbed to a portion of the upper surface of the first magnetic layer 21 that is not covered with the first resist layer 91. Thereby, palladium adsorbed to the upper surface of the first magnetic layer 21 is formed as the catalyst layer 30A. Next, electroless copper plating is performed by immersing in an electroless copper plating solution, and a first wiring layer 30B having a copper ratio of 99wt% or less and a nickel ratio of 0.1wt% or more is formed on the upper side of the catalyst layer 30A. The electroless copper plating solution is an alkaline solution and contains copper salts such as copper chloride and copper sulfate. On the other hand, the metal magnetic powder 20B is made of iron, and has a greater ionization tendency than copper, which is the material of the first wiring layer 30B. Therefore, in the inductor wiring process, iron on the surface of the metal magnetic powder 20B melts, and instead, copper forms a film on the surface of the metal magnetic powder 20B.

Here, since the electroless copper plating solution also enters the minute gap between the base material 20A and the metal magnetic powder 20B, substitution of iron by copper occurs not only on the exposed surface side of the metal magnetic powder 20B but also on the surface of the metal magnetic powder 20B on the inner side of the base material 20A. Copper deposited on the surface of the metal magnetic powder 20B on the inner side of the base material 20A functions as an anchor 34.

In this way, the coating amount is adjusted so that copper formed on the surface of the metal magnetic powder 20B on the inner side of the base material 20A covers more than one third of the surface area of the metal magnetic powder 20B. Specifically, the time of application of the electroless copper plating voltage, the amount of current, the copper content of the plating solution, the catalyst content, and the like may be adjusted.

After electroless copper plating, electrolytic copper plating is performed as shown in fig. 10. Thereby, the second wiring layer 30C having a copper ratio of 99wt% or more is formed on the surface of the first wiring layer 30B. Thus, the inductor wiring 30 is formed by adsorption of palladium, electroless copper plating, and electrolytic copper plating.

After the inductor wiring processing step, a first resist layer removal step of removing the first resist layer 91 is performed. As shown in fig. 11, in the first resist layer removal step, the first resist layer 91 is separated from the first magnetic layer 21 and peeled off.

After the first resist layer removal process, a second covering process is performed. As shown in fig. 12, in the second covering step, the second resist layer 92 covering the upper surface of the first magnetic layer 21 and the upper surface of the second wiring layer 30C is patterned at the portion where the first vertical wiring 51 and the second vertical wiring 52 are not formed. The photolithography method in the second covering step is the same as that in the first covering step, and therefore, a detailed description thereof is omitted.

After the second covering process, a vertical wiring process is performed to form the first vertical wiring 51 and the second vertical wiring 52. In the vertical wiring processing step, electrolytic copper plating is performed, and the first vertical wiring 51 and the second vertical wiring 52 having a copper ratio of 99wt% or more are formed in the portion of the upper surface of the second wiring layer 30C that is not covered with the second resist layer 92.

After the vertical wiring processing step, a second resist layer removal step of removing the second resist layer 92 is performed. In the second resist layer removing step, the second resist layer 92 is separated from the first magnetic layer 21 and peeled off in the same manner as in the first resist layer removing step.

After the second resist layer removal step, a second magnetic layer processing step is performed. As shown in fig. 13, in the second magnetic layer processing step, first, a magnetic material composed of a base material 20A and a metal magnetic powder 20B is filled from the upper surface of the first magnetic layer 21 to the upper side in the stacking direction of the upper ends of the first vertical wiring 51 and the second vertical wiring 52. Next, grinding is performed from the upper side in the stacking direction until the upper ends of the first vertical wiring 51 and the second vertical wiring 52 are exposed, thereby forming the inner magnetic circuit portion 22, the second magnetic layer 24, and the outer magnetic circuit portion 23, which are not shown.

After the second magnetic layer processing step, a cover layer processing step is performed. As shown in fig. 14, in the capping layer processing step, the solder resist functioning as the capping layer 60 is patterned by photolithography at a portion where the external electrode 70 is not formed, out of the upper surface of the second magnetic layer 24, the upper surface of the first vertical wiring 51, and the upper surface of the second vertical wiring 52.

After the cover layer processing step, a base substrate removal step is performed. As shown in fig. 15, in the base substrate removal step, the base substrate 80 with copper foil is removed. Specifically, the base substrate 81 is separated from the first magnetic layer 21 and peeled off. Next, the copper foil is removed by etching. The first magnetic layer 21 is ground from the lower side in the lamination direction until the dimension from the lower end of the first magnetic layer 21 to the upper end of the cover layer 60 reaches a desired value.

After the base substrate removal step, an external electrode processing step is performed. As shown in fig. 16, an external electrode 70 is formed on the upper surface of the first vertical wiring 51. In addition, an external electrode 70 is formed on the upper side of the second vertical wiring 52. The external electrode 70 is electroless plated with copper, nickel, and gold, respectively, to form a copper layer 70A, a nickel layer 70B, and a gold layer 70C, respectively. Thereby, the external electrode 70 of a 3-layer structure is formed.

After the external electrode processing step, a singulation process step is performed. Specifically, as shown in fig. 17, singulation is performed by cutting along a broken line DL. Thereby, the inductor component 10 can be obtained. At this time, the first dummy wirings 41 and the second dummy wirings 42 included in the broken line DL are exposed on the side surface of the inductor component 10.

Next, effects of the first embodiment will be described.

(1) According to the inductor component 10 of the first embodiment described above, the anchor portion 34 extends from the surface of the lower side of the catalyst layer 30A constituting the main surface MF of the inductor wiring 30. The anchor 34 covers the surface of the metal magnetic powder 20B that is present in the base material 20A of the first magnetic layer 21 in a dispersed manner. Therefore, the anchoring effect is obtained between the inductor wiring 30 and the first magnetic layer 21 by the anchor 34. As a result, the adhesion between the inductor wiring 30 and the first magnetic layer 21 is improved. In this way, in the inductor component 10, the inductor wiring 30 is directly laminated on the first magnetic layer 21 while ensuring the required adhesion between the inductor wiring 30 and the first magnetic layer 21.

(2) According to the inductor component 10 of the first embodiment described above, the metal magnetic powder 20B covered with the anchor 34 includes a cross section in which more than one third of the surface of the metal magnetic powder 20B is covered with the anchor 34 when the cross section is viewed. Therefore, the anchor 34 is relatively large, and therefore the inductor wiring 30 and the first magnetic layer 21 can be reliably brought into close contact.

(3) According to the method for manufacturing the inductor component 10 of the first embodiment, in the inductor wiring processing step, the metal magnetic powder 20B is exposed to a part of the surface of the first magnetic layer 21, and the first magnetic layer 21 is immersed in the plating solution, whereby the inductor wiring 30 is formed on a part of the surface of the first magnetic layer 21. Therefore, by allowing the plating liquid to enter between the base material 20A and the metal magnetic powder 20B in the first magnetic layer 21, the anchor portion 34 can be formed on the surface of the metal magnetic powder 20B on the inner side of the base material 20A.

(4) According to the method for manufacturing the inductor component 10 of the first embodiment, electroless copper plating is performed by immersing in the electroless copper plating solution, and the first wiring layer 30B having a copper ratio of 99wt% or less and a nickel ratio of 0.1wt% or more is formed on the upper surface of the catalyst layer 30A. Therefore, in the case of forming the first wiring layer 30B by sputtering or the like, for example, damage to the surface of the first magnetic layer 21 is relatively small, and the amount of the metal magnetic powder 20B in the first magnetic layer 21 can be formed without excessively reducing the amount.

(5) According to the inductor component 10 of the first embodiment, the material of the metal magnetic powder 20B, i.e., iron, tends to be ionized more than the material of the first wiring layer 30B, i.e., copper. Therefore, iron having a large ionization tendency is formed as ions between the copper salt in the electroless copper plating and the surface of the metal magnetic powder 20B, and copper having a small ionization tendency is precipitated. Thus, even if the substrate 20A is relatively dense with the metal magnetic powder 20B, copper can be precipitated to cover the surface of the metal magnetic powder 20B.

(6) According to the inductor component 10 of the first embodiment described above, the thickness TC of the second wiring layer 30C is 5 times or more the thickness TB of the first wiring layer 30B. Accordingly, the thickness TA of the inductor wiring 30 can be increased accordingly, and thus the dc resistance can be reduced.

(7) According to the method for manufacturing the inductor component 10 of the first embodiment, electrolytic copper plating is performed, and the second wiring layer 30C having a copper ratio of 99wt% or more and a nickel ratio of less than or equal to the detection limit is formed on the surface of the first wiring layer 30B. Therefore, the second wiring layer 30C having a larger thickness can be efficiently formed as compared with electroless copper plating.

(8) According to the inductor component 10 of the first embodiment described above, the catalyst layer 30A is arranged on the first magnetic layer 21 side of the first wiring layer 30B. The catalyst layer 30A activates copper deposition in electroless copper plating. Therefore, palladium as a catalyst is adsorbed in a layered form on the entire surface of the first magnetic layer 21, and thus copper deposition occurs on the entire surface of the first magnetic layer 21 during electroless copper plating, and the first wiring layer 30B having a uniform thickness is easily formed.

(9) According to the inductor component 10 of the first embodiment, the base material 20A includes an epoxy resin and an inorganic filler. Therefore, even if the thickness of the first magnetic layer 21 is reduced, physical defects such as cracks are less likely to occur, and sufficient strength can be maintained without providing an insulating substrate or the like.

(10) According to the inductor component 10 of the first embodiment described above, the cover layer 60 covers the upper surface of the third layer L3. Therefore, insulation from the outside is easily ensured.

(11) According to the inductor component 10 of the first embodiment described above, the average particle diameter of the metal magnetic powder 20B is 5.0 μm or less. The average particle diameter of the metal magnetic powder 20B is one tenth or less of the wiring width of the wiring body 31 of the inductor wiring 30. Accordingly, the average particle diameter of the metal magnetic powder 20B is correspondingly smaller. Therefore, the surface area of the metal magnetic powder 20B in contact with the inductor wiring 30 increases, and the number of anchor portions 34 is easily set much more. As a result, a stable anchoring effect is easily obtained.

< second embodiment >

A second embodiment of the inductor component will be described below.

As shown in fig. 18, the inductor member 110 has a structure in which six plate-like layers are stacked in the thickness direction as a whole. In the following description, a lamination direction in which six layers are laminated will be described as an up-down direction.

The first layer L11 has a rectangular shape when viewed from the up-down direction. The first layer L11 is constituted by only the first magnetic layer 121. As shown in fig. 21, in the first magnetic layer 121, metal magnetic powder 120B is present dispersedly in a base material 120A made of an insulating material. Therefore, the first magnetic layer 121 is entirely made of a magnetic material. Specifically, the base material 120A is composed of an epoxy resin and an inorganic filler having an average particle diameter of 1.0 μm or less, the metal magnetic powder 120B is an alloy composed of iron, silicon and chromium, and the average particle diameter of the metal magnetic powder 120B is 5.0 μm or less. In the present embodiment, the first layer L11 is the lowest layer in the up-down direction. That is, one of the vertical directions on which the external electrode 230 described later is provided is set as an upper side, and the opposite side is set as a lower side.

As shown in fig. 18, a second layer L12, which is rectangular when viewed from the up-down direction, is formed on the upper side in the stacking direction of the first layer L11, similar to the first layer L11. In the present embodiment, the surface of the second layer L12 that contacts the first layer L11 is the main surface MF2 of the second layer L12. The second layer L12 is constituted by the second magnetic layer 122, the first inductor wiring 130, the first dummy wiring 141, the first connection wiring 146, and the first insulating portion 181. The first inductor wiring 130 is composed of a first wiring body 131 having a substantially constant wiring width, a first pad 132 connected to a first end of the first wiring body 131, and a second pad 133 connected to a second end of the first wiring body 131.

As shown in fig. 19, the first wiring body 131 of the first inductor wiring 130 extends in a spiral shape centering around the center of the surface of the rectangular second layer L12 opposite to the main surface MF2 when viewed from the upper side in the vertical direction. Specifically, the first wiring body 131 of the first inductor wiring 130 is wound in a spiral shape clockwise from the first end on the radial outside toward the second end on the radial inside.

In the present embodiment, the first inductor wiring 130 is wound at an angle of 540 degrees. Therefore, in the present embodiment, the number of turns of the first inductor wiring 130 wound is 1.5 turns. In the present embodiment, when the second layer L12 is viewed from the upper side in the vertical direction, the side on which the first end of the first wiring body 131 is disposed is set to the first end side, and the side on which the second end of the first wiring body 131 is disposed is set to the second end side in the longitudinal direction of the rectangular second layer L12.

A first pad 132 is connected to a first end of one side in the extending direction of the first wiring body 131. The first pad 132 has a substantially quadrangular shape when viewed from the up-down direction. The first pad 132 constitutes a first end portion of the first inductor wiring 130. The first pads 132 are arranged near corners of the rectangular second layer L12 when viewed from the up-down direction. The wiring width of the first pad 132 is larger than the wiring width of the first wiring body 131 connected to the first pad 132.

A second pad 133 is connected to a second end of the other side in the extending direction of the first wiring body 131. The second pad 133 is circular in shape when viewed from the up-down direction. The second pad 133 constitutes a second end of the first inductor wiring 130. The diameter of the circle of the second pad 133 is larger than the first wiring body 131 connected to the second pad 133.

The first dummy wirings 141 are connected to the first pads 132. The first dummy wirings 141 extend from a portion of the first pads 132 opposite to the first wiring main body 131 to the side of the second layer L12 and are exposed at the outer surface of the inductor component 110.

In the second layer L12, the first connection wiring 146 is arranged near a corner on the opposite side of the rectangular second layer L12 from the first pad 132 in the short side direction and on the first end side in the long side direction, as viewed from the up-down direction. The first connection line 146 is line-symmetrical with respect to a straight line passing through the center of the second layer L12 in the short side direction and extending in the long side direction of the second layer L12 as a symmetry axis.

As shown in fig. 21, the first inductor wiring 130 has a structure in which a first wiring layer 130B and a second wiring layer 130C are laminated in this order from the first magnetic layer 121 side constituting the first layer L11. The first wiring layer 130B of the first inductor wiring 130 is in contact with the upper surface of the first magnetic layer 121, and constitutes a large part of the main surface MF2 of the second layer L12. In fig. 21, only the first inductor line 130 and the first magnetic layer 121 are illustrated, and other structures are not illustrated.

The ratio of copper in the material of the first wiring layer 130B is 99wt% or less, and the ratio of nickel is 0.1wt%. The thickness TB2 of the first wiring layer 130B is one tenth or less of the wiring width of the inductor wiring 30. In the present embodiment, the thickness TB2 of the first wiring layer 130B is 2.0 μm. Here, in one observation field of view of a cross section along the stacking direction observed with a 1500-fold microscope, a dimension in the stacking direction from the upper end of the first magnetic layer 121 to the upper end of the first wiring layer 130B was measured at 3 points, and the thickness TB2 of the first wiring layer 130B was determined as an average value of the measured values at these 3 points. In the present embodiment, the thickness TB2 of the first wiring layer 130B is substantially constant. Further, the wiring width of the first inductor wiring 130 is determined as a 3-point average value near the center in the extending direction in the width dimension of the first inductor wiring 130.

The second wiring layer 130C is directly laminated on the upper surface of the first wiring layer 130B. In addition, the second wiring layer 130C covers a slightly wider range than the first wiring layer 130B from the upper side in the stacking direction. That is, the side surface of the first wiring layer 130B facing the direction orthogonal to the stacking direction is covered with the second wiring layer 130C. Further, a part of the outer surface of the second wiring layer 130C constitutes a part of the main surface MF2 of the first inductor wiring 130.

The thickness TC2 of the second wiring layer 130C is 5 times or more the thickness TB2 of the first wiring layer 130B. In the present embodiment, the thickness TC2 of the second wiring layer 130C is 45 μm. Therefore, as shown in fig. 20, the thickness of the first inductor wiring 130 composed of the first wiring layer 130B and the second wiring layer 130C is 47 μm. In one observation field including a cross section in the stacking direction, a dimension in the stacking direction from the upper end of the first wiring layer 130B to the upper end of the second wiring layer 130C was measured at 3 points in a view of a 1500-fold microscope, and the thickness TC of the second wiring layer 130C was determined as an average value of the measured values at these 3 points. The ratio of copper in the material of the second wiring layer 130C is 99wt% or more, and the ratio of nickel is the detection limit or less.

The anchor 134 extends from the main surface MF2 of the first inductor wiring 130. In the present embodiment, the anchor 134 extends from either one of the first wiring layer 130B and the second wiring layer 130C constituting the main surface MF2 of the first inductor wiring 130. The anchor 134 covers the surface of the metal magnetic powder 120B in contact with the main surface MF2 among the plurality of metal magnetic powders 120B in the first magnetic layer 121. Therefore, the anchor 134 extends from the main surface MF2 into between the base material 120A and the metal magnetic powder 120B in the first magnetic layer 121. The metal magnetic powder 120B covered with the anchor 134 includes a cross section in which one third or more of the surface of the metal magnetic powder 120B is covered with the anchor 134 when the cross section is viewed.

As shown in fig. 18, in the second layer L12, the side surface of the first inductor wiring 130, the side surface of the first dummy wiring 141, and the side surface of the first connection wiring 146 are covered with the first insulating portion 181. That is, the first inductor wiring 130, the first dummy wiring 141, and the first connection wiring 146 are surrounded by the first insulating portion 181. The first insulating portion 181 is an insulating resin having higher insulation than the first inductor wiring 130. The portions other than the first inductor wiring 130, the first dummy wiring 141, the first connection wiring 146, and the first insulating portion 181 are the second magnetic layer 122. Therefore, the second magnetic layer 122 is disposed at the central portion of the second layer L12, at both end portions in the short side direction of the second layer L12, and at the first end side portion in the long side direction of the second layer L12. The material of the second magnetic layer 122 is the same as that of the first magnetic layer 121.

A third layer L13 having a rectangular shape when viewed from the top-bottom direction, similar to the second layer L12, is laminated on the upper surface of the second layer L12. The third layer L13 is constituted by the second insulating portion 182, the first via 191, the second via 192, the third via 193, and the third magnetic layer 123.

The first via hole 191 is disposed above the first pad 132 of the second layer L12 and connected to the first pad 132. The second via hole 192 is disposed above the first connection line 146 of the second layer L12, and is connected to the first connection line 146. The third via 193 is disposed above the second pad 133 of the second layer L12 and connected to the second pad 133. The first through-hole 191, the second through-hole 192, and the third through-hole 193 are columnar, and the axial direction coincides with the lamination direction. The dimensions of the first via hole 191, the second via hole 192, and the third via hole 193 in the lamination direction are the same as those of the third layer L13. Accordingly, the first via hole 191, the second via hole 192, and the third via hole 193 penetrate the third magnetic layer 123 in the lamination direction.

The second insulating portion 182 covers the first inductor wiring 130, the first dummy wiring 141, the first connection wiring 146, and the first insulating portion 181 from the upper side. That is, the second insulating portion 182 covers all surfaces of the upper surfaces of the wirings of the second layer L12 except for the portions where the first via 191, the second via 192, and the third via 193 are disposed. The second insulating portion 182 has a shape covering a slightly wider range than the outer edges of the first inductor wiring 130, the first dummy wiring 141, and the first connecting wiring 146 when viewed from the up-down direction. The second insulating portion 182 is an insulating resin having the same insulating property as the first insulating portion 181. In the present embodiment, the first insulating layer is formed by the first insulating portion 181 and the second insulating portion 182.

In the third layer L13, the portions other than the first via hole 191, the second via hole 192, the third via hole 193, and the second insulating portion 182 are the third magnetic layer 123. Therefore, the third magnetic layer 123 is disposed at the central portion of the third layer L13, at both end portions of the third layer L13 in the short side direction, and at the first end portion of the third layer L13 in the long side direction. The third magnetic layer 123 is made of the same magnetic material as the first magnetic layer 121 described above.

A fourth layer L14 having a rectangular shape when viewed from the top-bottom direction, similar to the third layer L13, is laminated on the top surface of the third layer L13. The fourth layer L14 is constituted by the second inductor wiring 135, the second dummy wiring 142, the second connection wiring 147, the third insulating portion 183, and the fourth magnetic layer 124. The second inductor wiring 135 is constituted by a second wiring body 136 having a substantially constant wiring width, a third pad 137 connected to a first end of the second wiring body 136, and a fourth pad 138 connected to a second end of the second wiring body 136. That is, the second inductor wiring 135 is laminated with the first inductor wiring 130 at an interval corresponding to the third layer L13 in the lamination direction. In the present embodiment, the third pad 137 is a first end portion of the second inductor wiring 135, and the fourth pad 138 is a second end portion of the second inductor wiring 135.

The second wiring body 136 of the second inductor wiring 135 extends in a spiral shape centering around the center of the surface of the fourth layer L14 opposite to the main surface MF3, when viewed from the vertical direction. Specifically, the second wiring body 136 of the second inductor wiring 135 is wound in a spiral shape counterclockwise from the first end on the radial outside toward the second end on the radial inside. That is, the direction in which the second inductor wiring 135 is wound is opposite to the direction in which the first inductor wiring 130 is wound.

In this embodiment, the second inductor wiring 135 is wound at an angle of 540 degrees. Therefore, in the present embodiment, the number of turns in which the second inductor wiring 135 is wound is 1.5 turns.

A third pad 137 is connected to a first end of one side in the extending direction of the second wiring body 136. The third pad 137 has a substantially quadrangular shape when viewed from the up-down direction. The third pad 137 constitutes a first end of the second inductor wiring 135. The third pad 137 is disposed near a corner of the rectangular fourth layer L14 when viewed in the vertical direction. The third pad 137 has a wider wiring width than the second wiring body 136 connected to the third pad 137.

A fourth pad 138 is connected to a second end of the other side in the extending direction of the second wiring body 136. The fourth pad 138 is circular in shape when viewed from the up-down direction. The fourth pad 138 is located on the upper side of the second pad 133 in the second layer L12, and is connected to the second pad 133 via the third via hole 193. The fourth pad 138 has a wider wiring width than the second wiring body 136 connected to the fourth pad 138. The fourth pad 138 constitutes a second end portion of the second inductor wiring 135.

The second dummy wiring 142 is connected to the third pad 137. The second dummy wirings 142 extend from a portion of the third pad 137 opposite to the second wiring main body 136 to a side surface of the fourth layer L14, and are exposed at an outer surface of the second inductor wiring 135.

In the fourth layer L14, the second connection wiring 147 is arranged near a corner on the opposite side of the third pad 137 in the short side direction and on the first end side in the long side direction of the rectangular fourth layer L14 as viewed from the up-down direction. The second connection wiring 147 is line-symmetrical with respect to a straight line passing through the center of the fourth layer L14 in the short side direction and extending in the long side direction of the fourth layer L14 as a symmetry axis. Further, in fig. 19, the second inductor wiring 135 and the second connection wiring 147 are indicated by broken lines.

Here, as shown in fig. 20, the third via 193 is integrated with the second inductor wiring 135. Although not shown, the second via hole 192 and the second dummy wiring 142 are also integrated with the second inductor wiring 135. The second connection wiring 147 is integrated with the first via hole 191. In the following description, these integrated products are referred to as the second conductive layer 200. The second conductive layer 200 is formed by stacking a third wiring layer 200A and a fourth wiring layer 200B. The third wiring layer 200A constitutes a part of the lower end side of the second conductive layer 200. Therefore, a portion of the third wiring layer 200A located below the first via 191 and the third via 193 is in contact with the first inductor wiring 130. In addition, a portion of the third wiring layer 200A located below the second via hole 192 is in contact with the first connection wiring 146. In the third wiring layer 200A, the lower portion except the first via hole 191, the second via hole 192, and the third via hole 193 is in contact with the upper surface of the second insulating portion 182. The material of the third wiring layer 200A includes titanium and chromium.

A fourth wiring layer 200B is laminated on the upper surface of the third wiring layer 200A. The ratio of copper in the material of the fourth wiring layer 200B is 99wt% or more. The upper end of the fourth wiring layer 200B is on the same plane as the upper end of the fourth layer L14.

As shown in fig. 18, in the fourth layer L14, the side surfaces of the second inductor wiring 135 are covered with the third insulating portion 183. Therefore, the third insulating portion 183 is interposed at a position where the distance between the second inductor wirings 135 is shortest. The third insulating portion 183 is an insulating resin having higher insulation than the second inductor wiring 135. The third insulating portion 183 has a curved shape as a whole.

Also, the portion other than the second inductor wiring 135, the second dummy wiring 142, the second connection wiring 147, and the third insulating portion 183 is the fourth magnetic layer 124. Therefore, the fourth magnetic layer 124 is disposed at the central portion of the fourth layer L14, at both end portions in the short side direction of the fourth layer L14, and at the first end portion in the long side direction of the fourth layer L14. The fourth magnetic layer 124 is made of the same material as the first magnetic layer 121.

A fifth layer L15 having a rectangular shape when viewed from the up-down direction, similar to the fourth layer L14, is laminated on the upper surface of the fourth layer L14. The fifth layer L15 is constituted by the fifth magnetic layer 125, the fourth insulating portion 184, the first columnar wiring 194, the second columnar wiring 195, and the third columnar wiring 196. The first columnar wiring 194, the second columnar wiring 195, and the third columnar wiring 196 penetrate the fifth layer L15 in the lamination direction.

The fourth insulating portion 184 covers the entire upper surface of the third insulating portion 183 and a portion of the upper surface of the second inductor wiring 135. Therefore, the fourth insulating portion 184 covers the third insulating portion 183 from the upper side. The fourth insulating portion 184 is an insulating resin having the same insulating property as the third insulating portion 183, and has a higher insulating property than the second inductor wiring 135. In the present embodiment, the second insulating layer is formed by the third insulating portion 183 and the fourth insulating portion 184.

In the fifth layer L15, the portions other than the first columnar wiring 194, the second columnar wiring 195, the third columnar wiring 196, and the fourth insulating portion 184 are the fifth magnetic layer 125. The fifth magnetic layer 125 is made of the same material as the first magnetic layer 121 described above, and is made of a magnetic material.

A sixth layer L16 having a rectangular shape when viewed from the up-down direction, similar to the fifth layer L15, is laminated on the upper surface of the fifth layer L15. The sixth layer L16 is constituted by the sixth magnetic layer 126, the fourth columnar wiring 197, the fifth columnar wiring 198, and the sixth columnar wiring 199.

The fourth columnar wiring 197 is arranged above the second connection wiring 147 in the fourth layer L14, and is connected to the second connection wiring 147 through the second columnar wiring 195. The sixth columnar wiring 199 is arranged above the third pad 137 in the fourth layer L14, and is connected to the third pad 137 via the first columnar wiring 194. The fourth columnar wiring 197 and the sixth columnar wiring 199 are prismatic, and the axial direction matches the stacking direction. The dimensions of the fourth columnar wirings 197 and the sixth columnar wirings 199 in the stacking direction are the same as those of the sixth layer L16. Therefore, the fourth columnar wiring 197 and the sixth columnar wiring 199 penetrate the sixth layer L16 in the stacking direction. That is, in this embodiment, the first vertical wiring is constituted by the first columnar wiring 194 and the sixth columnar wiring 199. In addition, a third vertical wiring is constituted by the second columnar wiring 195 and the fourth columnar wiring 197.

The fifth columnar wiring 198 is disposed above the fourth pad 138 of the second inductor wiring 135 in the fourth layer L14, and is connected to the fourth pad 138 via the third columnar wiring 196. That is, in this embodiment, the second vertical wiring is constituted by the third columnar wiring 196 and the fifth columnar wiring 198. In fig. 19, the fourth columnar wiring 197, the fifth columnar wiring 198, and the sixth columnar wiring 199 are indicated by two-dot chain lines.

As shown in fig. 18, in the sixth layer L16, portions other than the fourth columnar wiring 197, the fifth columnar wiring 198, and the sixth columnar wiring 199 are the sixth magnetic layer 126. Accordingly, the sixth magnetic layer 126 is laminated on the upper side of the second inductor wiring 135. The sixth magnetic layer 126 is made of the same material as the first magnetic layer 121 described above, and is made of a magnetic material.

As shown in fig. 20, an external electrode 230 is stacked on the upper side of the fifth columnar wiring 198. Further, an external electrode 230 is connected to the upper surface of the fourth columnar wiring 197 and the sixth columnar wiring 199. In fig. 18, the external electrode 230 is not illustrated.

Next, a method of manufacturing the inductor component 110 according to the second embodiment will be described.

As shown in fig. 22, the method for manufacturing the inductor component 110 includes a first magnetic layer processing step, a first covering step, a first wiring layer processing step, a first resist layer removal step, a second covering step, a second wiring layer processing step, a second resist layer removal step, and a first insulating layer processing step, and forms the first inductor wiring 130. The method for manufacturing the inductor component 110 includes a third wiring layer processing step, a third covering step, a fourth wiring layer processing step, a fourth covering step, a vertical wiring processing step, a fourth resist layer removal step, a third resist layer removal step, a second insulating layer processing step, a second magnetic layer processing step, a base substrate removal step, and an external electrode processing step, and forms a second inductor wiring 135 and the like.

In manufacturing the inductor component 110, first, a first magnetic layer processing step is performed. As shown in fig. 23, a base substrate 210 with copper foil is prepared. The base substrate 211 of the base substrate 210 with copper foil is plate-shaped. A copper foil 212 is laminated on a layer on the upper side in the lamination direction of the base substrate 211. As shown in fig. 24, a first magnetic layer 121 composed of a base material 120A and a metal magnetic powder 120B is formed on the upper surface of the copper foil 212 in the base substrate with copper foil 210. When the first magnetic layer 121 is formed, an insulating resin containing the metal magnetic powder 120B is applied, and the insulating resin is solidified by press working to become the base material 120A. Then, the upper side portions of the base material 120A and the metal magnetic powder 120B are ground so that the dimension of the first magnetic layer 121 in the up-down direction becomes a desired dimension. Preferably, during grinding, the process parameters during grinding are adjusted so that a minute gap is formed at the interface between the base material 120A and the metal magnetic powder 120B.

After the second magnetic layer processing step, a first covering step is performed. As shown in fig. 25, in the first covering step, the first resist layer 221 covering the portion of the upper surface of the first magnetic layer 121 where the first wiring layer 130B is not formed is patterned. Specifically, first, a photosensitive dry film resist is entirely coated on the upper surface of the first magnetic layer 121. Next, a portion of the upper surface of the first magnetic layer 121 where the first wiring layer 130B is not formed is exposed. As a result, the exposed portions of the coated dry film resist cure. Then, the uncured portions of the coated dry film resist are peeled off by a chemical solution. Thereby, a cured portion in the coated dry film resist is formed as the first resist layer 221. On the other hand, in the portion of the coated dry film resist that is removed by the chemical solution but not covered by the first resist layer 221, the first magnetic layer 121 is exposed.

After the first covering process, a first wiring layer processing process is performed. As shown in fig. 26, in the first wiring layer processing step, a first wiring layer 130B is formed on the upper surface of the first magnetic layer 121. Specifically, electroless copper plating is performed by immersing the first wiring layer 130B in an electroless copper plating solution, wherein the ratio of copper to nickel is 99wt% or less and the ratio of nickel to nickel is 0.1wt% or more on the upper surface of the first magnetic layer 121 exposed from the first resist layer 221. The electroless copper plating solution is an alkaline solution and contains copper salts such as copper chloride and copper sulfate. On the other hand, the metal magnetic powder 120B is made of iron, and has a greater ionization tendency than copper, which is a material of the first wiring layer 130B. Therefore, in the first wiring layer processing step, iron on the surface of the metal magnetic powder 120B melts, and copper is formed on the surface of the metal magnetic powder 120B instead.

Here, since the electroless copper plating solution also enters the minute gap between the base material 120A and the metal magnetic powder 120B, substitution of iron by copper occurs not only on the exposed surface side of the metal magnetic powder 120B but also on the surface of the metal magnetic powder 120B on the inner side of the base material 120A. Copper deposited on the surface of the metal magnetic powder 120B on the inner side of the base material 120A functions as an anchor 134. Thus, the anchor portion 134 extending from the lower surface of the first wiring layer 130B is formed by electroless copper plating.

After the first wiring processing step, a first resist layer removal step of removing the first resist layer 221 is performed. As shown in fig. 27, in the first resist layer removal step, the first resist layer 221 is separated from the first magnetic layer 121 and peeled off.

After the first resist layer removal process, a second covering process is performed. As shown in fig. 28, in the second covering step, the second resist layer 222 covering the portion of the upper surface of the first magnetic layer 121 where the second wiring layer 130C is not formed is patterned. In this embodiment mode, the second resist layer 222 is patterned so as to be exposed in a slightly wider range than the first wiring layer 130B. The photolithography method in the second covering step is the same as that in the first covering step, and therefore, a detailed description thereof is omitted.

After the second covering process, a second wiring layer processing process is performed. In the second wiring layer processing step, the second wiring layer 130C is formed at a portion not covered with the second resist layer 222. Specifically, the second wiring layer 130C having a copper ratio of 99wt% or more is formed on the surface which is subjected to electrolytic copper plating and is not covered with the second resist layer 222. At this time, as shown in fig. 21, the portion of the end of the second wiring layer 130C is directly adhered to the first magnetic layer 121 not covered by the first wiring layer 130B. Therefore, the plating solution at the time of electrolytic copper plating enters the gap between the base material 120A and the metal magnetic powder 120B for the first magnetic layer 121 in contact with the lower surface of the second wiring layer 130C. Copper deposited from the plating solution entering the gap functions as an anchor 134. In the present embodiment, the first wiring process and the second wiring process are inductor wiring processes.

After the second wiring layer processing step, a second resist layer removal step is performed. As shown in fig. 29, in the second resist layer removal step, the second resist layer 222 is separated from the first magnetic layer 121 and peeled off.

After the second resist layer removal process, a first insulating layer processing process is performed. As shown in fig. 30, the first inductor wiring 130 is covered from the upper side in the lamination direction by an insulating material. Thereby, the first insulating layer including the first insulating portion 181 and the second insulating portion 182 is formed over the entire upper surface of the first magnetic layer 121 and the first inductor wiring 130.

After the first insulating layer processing step, a third wiring processing step is performed. As shown in fig. 31, first, a hole penetrating the second insulating portion 182 is formed by laser light at a portion where the third via hole 193 is formed in the upper surface of the first inductor wiring 130. Thus, the upper surface of the first inductor wiring 130 is exposed at the portion where the third via 193 is formed. Next, from the upper side in the stacking direction, the third wiring layer 200A functioning as a seed layer is formed by sputtering. The material of the third wiring layer 200A includes titanium and chromium.

After the third wiring processing step, a third covering step is performed. In the third covering step, the third resist layer 223 covering the portion of the surface of the third wiring layer 200A where the fourth wiring layer 200B is not formed is patterned. The photolithography method in the third coating step is the same as that in the first coating step, and thus a detailed description thereof is omitted.

After the third covering process, a fourth wiring layer processing process is performed. In the fourth wiring layer processing step, electrolytic copper plating is performed, and the fourth wiring layer 200B having a copper ratio of 99wt% or more is formed in a portion of the surface of the third wiring layer 200A that is not covered with the third resist layer 223.

After the fourth wiring processing step, a fourth covering step is performed. In the fourth covering step, as shown in fig. 32, the fourth resist layer 224 covering the portion where the vertical wiring is not formed is patterned. That is, although not shown, only the portions where the first columnar wiring 194, the second columnar wiring 195, the third columnar wiring 196, the fourth columnar wiring 197, the fifth columnar wiring 198, and the sixth columnar wiring 199 are formed are exposed from the fourth resist layer 224.

After the fourth covering process, a vertical wiring process is performed. In the vertical wiring processing step, electrolytic copper plating is performed, and vertical wirings having a copper ratio of 99wt% or more are formed in the portion of the surface of the second wiring layer 130C not covered with the fourth resist layer 224. That is, the third columnar wiring 196 and the fifth columnar wiring 198 are formed. Although not shown, first columnar wiring 194, second columnar wiring 195, fourth columnar wiring 197, and sixth columnar wiring 199 are also formed.

After the vertical wiring processing step, a fourth resist layer removal step and a third resist layer removal step are performed simultaneously. Specifically, as shown in fig. 33, the third resist layer 223 and the fourth resist layer 224 are separated from the first magnetic layer 121 and peeled off. Then, the third wiring layer 200A functioning as a seed layer exposed on the surface is removed by etching.

After the third resist layer removal process, a second insulating layer processing process is performed. As shown in fig. 34, in the second insulating layer processing step, an insulating resin is coated on the upper surface. Specifically, first, the insulating resin is applied from the upper side in the lamination direction to the extent that the fourth wiring layer 200B is entirely covered. Next, the portion where the fourth insulating portion 184 is formed is exposed. Then, uncured portions of the coated insulating resin are peeled off by a chemical solution. As a result, as shown in fig. 35, the exposed portions of the applied insulating resin are cured, and the third insulating portion 183 and the fourth insulating portion 184 are formed. Then, as shown in fig. 36, portions of the first insulating layer including the first insulating portion 181 and the second insulating portion 182 where the first insulating portion 181 and the second insulating portion 182 are not formed are removed by laser light.

After the second insulating layer processing step, a second magnetic layer processing step is performed. As shown in fig. 37, in the second magnetic layer processing step, the magnetic material is filled up to the upper side in the stacking direction than the upper end of the fifth columnar wiring 198. Next, grinding is performed from the upper side in the stacking direction until the upper ends of the vertical wirings are exposed. Thereby, the second magnetic layer 122, the third magnetic layer 123, the fourth magnetic layer 124, the fifth magnetic layer 125, and the sixth magnetic layer 126 are formed.

After the second magnetic layer processing step, a base substrate removal step is performed. As shown in fig. 38, in the base substrate removal step, the base substrate 210 with copper foil is removed. Specifically, the base substrate 211 is separated from the first magnetic layer 121 and peeled off. Next, the copper foil is removed by etching. The first magnetic layer 121 is ground from the lower side in the lamination direction until the dimension from the lower end of the first magnetic layer 121 to the upper end of the sixth magnetic layer 126 becomes a desired value.

After the base substrate removal step, an external electrode processing step is performed. Specifically, the external electrode 230 having a single layer or a stacked structure including any one of copper, nickel, gold, and tin is formed on the upper surface of each vertical wiring, that is, on the upper surfaces of the fourth columnar wiring 197, the fifth columnar wiring 198, and the sixth columnar wiring 199 by electroless plating, electrolytic plating, printing, sputtering, or the like.

After the external electrode processing step, a singulation step is performed. Specifically, as shown in fig. 39, singulation is performed by cutting along a broken line DL. Thereby, the inductor component 110 can be obtained. At this time, the first dummy wirings 141 and the second dummy wirings 142 included in the dotted line DL are exposed on the side surface of the inductor component 110.

Next, effects of the second embodiment will be described. According to the second embodiment, the following effects are obtained in addition to the effects (1) to (7), (9) and (11) of the first embodiment.

(12) According to the inductor component 110 of the second embodiment described above, not only the first wiring layer 130B but also the lower surface of the second wiring layer 130C constitutes a part of the main surface MF2 of the first inductor wiring 130. Therefore, the anchor 134 also extends from the lower surface of the second wiring layer 130C, and a larger anchor effect between the first inductor wiring 130 and the first magnetic layer 121 is easily obtained.

(13) According to the inductor component 110 of the second embodiment described above, the anchor portion 134 extends from the main surface MF2 of the first inductor wiring 130, while the anchor portion does not extend from the main surface MF3 of the second inductor wiring 135. In addition, the second inductor wiring 135 is laminated with a space from the first inductor wiring 130 in the lamination direction. Therefore, the degree of freedom in design when stacking a plurality of inductor wirings is improved.

Each of the above embodiments can be modified as follows. The embodiments and the following modifications can be combined and implemented within a range that is not technically contradictory.

In each of the above embodiments, the inductor wiring may be any wiring that can apply inductance to the inductor member by generating magnetic flux in the magnetic layer when current flows.

In the above embodiments, the shape of the inductor wiring is not limited to the examples of the embodiments. For example, the inductor wiring may be a curve of less than 1.0 turns or a straight line of 0 turns. Further, some of the plurality of inductor wirings may have a different shape from other inductor wirings. In each embodiment, the inductor wiring may be curved.

In the first embodiment, a plurality of inductor wirings 30 may be arranged in a direction parallel to the main surface MF, or a plurality of inductor wirings 30 may be provided in the same layer. In this case, since the plurality of inductor wirings 30 are provided, the inductance as a whole is increased, and the inductors are arranged in the same layer, so that the size in the entire lamination direction can be prevented from becoming excessively large. The inductor component 10 having the plurality of inductor wires 30 provided in the same layer may be divided into a plurality of inductor components for use.

In the above embodiments, the wiring structure of the inductor wiring is not limited to the examples of the embodiments. For example, in the inductor wiring, the shapes of the first pad and the second pad may be changed, or the first pad and the second pad themselves may be omitted.

In the first embodiment, the catalyst layer 30A and the second wiring layer 30C may be omitted from the inductor wiring 30, and the inductor wiring 30 may be constituted by only the first wiring layer 30B. In this case, the lower surface of the first wiring layer 30B constitutes the main surface MF of the inductor wiring 30, and the anchor portion 34 may extend from the lower surface of the first wiring layer 30B.

In the above embodiments, the amount of the anchor portion covering is not limited to the examples of the above embodiments. For example, the anchor may not cover all of the surface of the metallic magnetic powder that is in contact, or may cover less than one third of the area. In this case, the metal magnetic powder covered with the anchor may not include a cross section in which one third or more of the surface of the metal magnetic powder is covered with the anchor when the metal magnetic powder is observed in cross section. The anchor may not cover the entire surface of the metal magnetic powder in contact with the main surface of the inductor wiring.

In the above embodiments, the formation of the anchor portion and adjustment of the amount of coverage of the anchor portion are not limited to the examples of the above embodiments. For example, in the first embodiment, when the surface treatment such as removal of the resin residue of the first magnetic layer 21 is performed, the interface state between the base material 20A and the metal magnetic powder 20B may be adjusted by the treatment time using an alkali-based chemical solution that dissolves the base material 20A of the first magnetic layer 21 and does not dissolve the metal magnetic powder 20B.

In the first embodiment, a minute gap between the base material 20A and the metal magnetic powder 20B is formed at the time of grinding, and an electroless copper plating solution flows into the gap in the inductor wiring process, but other known methods may be used as long as the anchor portion 34 can be formed. In particular, even when there is no clear gap at the interface between the base material 20A and the metal magnetic powder 20B, the electroless copper plating solution intrudes along the interface between the base material 20A and the metal magnetic powder 20B, and substitution of iron by copper described above occurs. Therefore, a gap may not be formed between the base material 20A and the metal magnetic powder 20B at the time of grinding.

In the second embodiment, the anchor 134 may not extend from the lower surface of the first wiring layer 130B, but may extend only from the lower surface of the second wiring layer 130C that forms a part of the main surface MF2 of the first inductor wiring 130.

In each of the above embodiments, the material of the first wiring layer is not limited to the example of each of the above embodiments. For example, the material of the first wiring layer may have a nickel content of 99wt% or less and a phosphorus content of 0.5wt% or more and 10wt% or less. In this case, by containing phosphorus, the stress of the nickel contained in the inductor component can be adjusted, and the residual stress of the inductor component can be relaxed. In addition, by including nickel in the first wiring layer, electromigration can be suppressed.

In each of the above embodiments, the material of the metal magnetic powder is not limited to the example of the above embodiment. For example, the material of the metal magnetic powder may contain a metal powder other than iron, or may not be a metal having a greater ionization tendency than the material of the first wiring layer. In this case, for example, if the grain boundary between the metal magnetic powder and the base material is relatively large, the plating solution can flow in, and thus the anchor portion can be formed.

In each of the above embodiments, the material of the second wiring layer may be a metal other than copper. In addition, the boundary surface between the second wiring layer and the first wiring layer is not necessarily clear, and a clear boundary may not be confirmed between the two in some cases.

In each of the above embodiments, the thickness of the second wiring layer may be smaller than 5 times the thickness of the first wiring layer.

In the first embodiment, the material of the catalyst layer 30A is not limited to the example of the embodiment. The material of the catalyst layer 30A may be any material that contains at least one metal selected from palladium, platinum, silver, and gold.

In the first embodiment, the thickness TA of the inductor wiring 30 is not limited to the example of the embodiment. When the thickness TA of the inductor wiring 30 is 40 μm or more, the dc resistance can be made relatively small. Further, if the thickness TA of the inductor wiring 30 is 120 μm or less, the wiring width with respect to the thickness TA can be made not to be excessively large.

In the first embodiment described above, the thickness TB of the first wiring layer 30B is not limited to the example of the embodiment described above. When the thickness TB of the first wiring layer 30B is 0.3 μm or more and 10 μm or less, it is easy to form it by electroless copper plating.

In each of the above embodiments, the material of the base material is not limited to the examples of the above embodiments. For example, when the material of the base material contains at least one resin selected from the group consisting of an epoxy resin, a phenolic resin and an acrylic resin, and an inorganic filler having an average particle diameter of 1 μm or less, it is preferable in terms of securing the strength of the magnetic layer. The material of the base material is not limited to this, and may be only a resin having insulating properties.

In each of the above embodiments, the average particle diameter of the metal magnetic powder is not limited to the examples of the above embodiments. If the average particle diameter of the metal magnetic powder is 5.0 μm or less, the number of anchor portions is easily increased. The average particle diameter of the metal magnetic powder may be larger than one tenth of the wiring width of the inductor wiring 30.

In the above embodiment, the boundaries of the magnetic layers in the respective layers may be integrated to such an extent that the interface cannot be confirmed, or may be separated from the interface.

Claims

1. An inductor component is provided with:

a magnetic layer in which metal magnetic powder is dispersed in a base material made of an insulating material; and

an inductor wiring laminated on the surface of the magnetic layer,

the inductor wiring has an anchor portion extending from a main surface on the magnetic layer side of the inductor wiring to cover a surface of the metal magnetic powder in the magnetic layer,

the inductor wiring includes a first wiring layer and a second wiring layer laminated on the opposite side of the first wiring layer from the magnetic layer,

the magnetic layer-side surface of the first wiring layer constitutes the main surface,

a portion of an outer surface of the second wiring layer constitutes the main surface of the inductor wiring.

2. The inductor component of claim 1 wherein,

the metal magnetic powder covered with the anchor includes a cross section in which more than one third of the surface is covered with the anchor when the metal magnetic powder is viewed in cross section.

3. The inductor component of claim 1 wherein,

the material of the metal magnetic powder includes a metal having a greater ionization tendency than the material of the first wiring layer.

4. An inductor component according to claim 1 or 3, wherein,

the first wiring layer is made of a material having a copper content of 99wt% or less and a nickel content of 0.1wt% or more.

5. An inductor component according to claim 1 or 3, wherein,

the nickel content in the material of the first wiring layer is 99wt% or less, and the phosphorus content is 0.5wt% or more and 10wt% or less.

6. An inductor component according to claim 1 or 3, wherein,

the second wiring layer is made of a material having a copper content of 99wt% or less.

7. An inductor component according to claim 1 or 3, wherein,

the thickness of the second wiring layer in the stacking direction is 5 times or more the thickness of the first wiring layer in the stacking direction.

8. An inductor component according to claim 1 or 3, wherein,

the inductor wiring is provided with a catalyst layer containing at least one metal selected from the group consisting of palladium, platinum, silver and gold,

the catalyst layer is arranged on the magnetic layer side of the first wiring layer,

the magnetic layer-side surface of the catalyst layer constitutes the main surface of the inductor wiring.

9. An inductor component according to claim 1 or 3, wherein,

the thickness of the inductor wiring is 40 μm or more and 120 μm or less,

the first wiring layer has a thickness of 0.3 μm or more and 10 μm or less.

10. An inductor component according to any one of claims 1 to 3, wherein,

the base material comprises at least one resin selected from epoxy resins, phenolic resins and acrylic resins, and an inorganic filler having an average particle diameter of 1 [ mu ] m or less.

11. An inductor component according to any one of claims 1 to 3, wherein,

the average particle diameter of the metal magnetic powder is below 5.0 mu m.

12. An inductor component according to any one of claims 1 to 3, wherein,

the average particle diameter of the metal magnetic powder is one tenth or less of the wiring width of the inductor wiring.

13. An inductor component according to any one of claims 1 to 3, wherein,

a second magnetic layer made of a magnetic material is formed on a layer of the inductor wiring on a side opposite to the magnetic layer,

a cover layer made of an insulating material is laminated on a surface of the second magnetic layer on a side opposite to the inductor wiring,

a vertical wiring is connected to the inductor wiring, the vertical wiring penetrating the second magnetic layer in a direction perpendicular to the main surface,

the vertical wiring is exposed from the cover layer,

an external electrode is connected to a portion of the vertical wiring exposed from the cover layer.

14. An inductor component according to any one of claims 1 to 3, wherein,

a plurality of the inductor wirings are arranged in a direction parallel to the main surface.

15. An inductor component according to any one of claims 1 to 3, wherein,

when the inductor wiring is set to the first inductor wiring,

the second inductor wiring other than the first inductor wiring is laminated with a space from the first inductor wiring in a direction perpendicular to the main surface,

The second inductor wiring does not have the anchor portion.